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Publication numberUS4394532 A
Publication typeGrant
Application numberUS 06/249,393
Publication date19 Jul 1983
Filing date31 Mar 1981
Priority date31 Mar 1981
Fee statusLapsed
Publication number06249393, 249393, US 4394532 A, US 4394532A, US-A-4394532, US4394532 A, US4394532A
InventorsArturo J. Aguayo
Original AssigneeRogers Corporation
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Multilayer current distribution systems and methods of fabrication thereof
US 4394532 A
A miniaturized bus bar is presented wherein a plurality of distribution prongs or fingers are mechanically and electrically bonded to a ribbon type capacitor which is defined by a pair of bus conductors and a ceramic spacer.
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What is claimed is:
1. A multilayer bus bar assembly including:
capacitor ribbon means, said ribbon means comprising a continuous elongated dielectric member of rectangular cross sections and electrically conductive coatings on a pair of oppositely disposed planar surfaces of the dielectric member; and
a plurality of distribution prong means on each of said planar surfaces, said prong means being comprised of an electrically conductive material, said prong means being mechanically and electrically bonded to respective coatings of said ribbon means.
2. The bus bar of claim 1 wherein said ribbon means dielectric member is comprised of a ceramic.
3. The bus bar of claim 2 wherein said ribbon means conductive coatings comprise metallized surfaces of the ceramic member.
4. The bus bar of claim 3 further comprising:
insulating means encapsulating said ribbon means, said prong means extending through said insulating means.
5. A method of forming a bus bar assembly including the following steps:
forming an elongated flat dielectric ceramic wafer having a rectangular cross-section;
applying a layer of conductive material to a pair of opposed surfaces of the flat ceramic wafer; and
electrically and mechanically bonding a plurality of transversely extending conductive distribution prongs to each of the conductive layers on the said opposed surfaces of the flat dielectric ceramic wafer.

1. Field of the Invention

This invention relates to bus bars and especially to relatively small or miniature bus bars. More particularly, this invention relates to multilayer bus bar assemblies, and the method of manufacture thereof, wherein the bus bar assembly incorporates a dielectric material having a high dielectric constant between bus conductors to provide a high capacitance bus bar.

2. Description of the Prior Art

Conventional bus bars of relatively small or miniature size have been known in the art for a number of years. Such bus bar devices are used for power and/or signal distribution in many systems, such as, for example, computer back panels and integrated circuit systems. Such prior art multilayer bus bars comprise at least two conductive plates (usually in the form of elongated strips or bars of copper) separated by an insulating film. A typical prior art bus bar of this type may use copper conductors having a thickness of about 10 mils, and the overall dimensions of the bus bar may be from about 0.019 to 0.120 inch thick, from about 0.150 to 0.200 inch wide and range in length up to about 16 inches. Typically, the separating insulating layer is a plastic dielectric film such as the polyester material known as MYLAR. The MYLAR separator layer and the conductive plates are bonded together by an adhesive. Conventional prior art bus bars of this type have relatively low capacitance which results in the devices being comparatively ineffective in attentuating high frequency noise. This high frequency noise is highly undesirable, especially when the bus bar is used for signal distribution.

One prior art approach to eliminating this noise problem involes connecting capacitors to the bus bar after the completion of the bus bar assembly. While this approach raised the capacitance and minimized the noise, it resulted in additional expense and time in manufacturing.

Another type of bus bar structure known in the prior art includes discrete capacitors disposed between a pair of bus conductors. These bus bars, by virtue of the use of miniaturized capacitors wherein the dielectric has a high dielectric constant have the desired high capacitance. Examples of such high capacitance bus bars are disclosed in U.S. Pat. Nos. 4,236,038 and 4,236,046 and in patent application Ser. No. 950,266, filed Oct. 10, 1978, now U.S. Pat. No. 4,266,091, all of which are owned by the assignee of the present invention. The capacitive elements utilized in the inventions of the above-reference patents and application include thin layers or chips of dielectric material, usually a ceramic with a high dielectric constant. The opposing surfaces of the chips are coated with a thin, integral and continuous film of conductive material and these conductive films are electrically connected to respective ones of the bus conductors.


The present invention overcomes the above-discussed disadvantages and other deficiencies of the prior art by providing novel and improved structure for and method of assembling a miniaturized bus bar assembly.

In accordance with the present invention a bus bar assembly is constructed by forming an elongated strip from a dielectric material having a high dielectric constant. The opposing surfaces of this strip are coated with a conductive material to form a ribbon capacitor. Bus bar distribution prongs or fingers are then mechanically and electrically bonded to the conductive surfaces of the ribbon capacitor. The whole assembly is subsequently encapsulated within a non-conductive sheath.

Accordingly, the present invention has as one of its numerous objectives the provision of novel miniaturized bus bar assemblies and methods for the fabrication thereof.


The present invention may be better understood and its numerous objectives and advantages will become apparent to those skilled in the art by reference to the accompanying drawing wherein like reference numerals refer to like elements in the several FIGURES and in which:

FIG. 1 is a perspective view of a portion of a laminated bus bar in accordance with the present invention with the insulating layer partially broken away for clarity of illustration.

FIG. 2 is a sectional view, taken along line 2--2, of the bus bar assembly of FIG. 1.


Referring to FIGS. 1 and 2 jointly, a miniaturized bus bar assembly prepared in accordance with the present invention is indicated generally at 10. Bus bar assembly 10 is formed by mechanically and electrically bonding distribution prongs or fingers 16 to the "plates" of a capacitor ribbon 11. Capacitor ribbon 11 is formed by applying conductive layers 14, such as silver or conductive adhesive, to opposing surfaces of an elongated chip 12. Chip 12 is formed from a ceramic material which has a high dielectric constant, preferably a dielectric constant in excess of 8,000. A ceramic material that may be used in the practice of the present invention is barium titanate. The thickness of chip 12 may range from about 0.005 inch to about 0.015 inch and have opposed face surface dimensions of about 0.2 inch by the length of the bus bar assembly 10. The bus bar distribution prongs or fingers 16 are copper elements, which may be tin plated. These prongs or fingers 16 are approximately 10 mils thick and have dimensions ranging from 0.018 inch by 0.100 inch to 0.032 inch by 0.150 inch. The prongs or fingers 16 are mechanically and electrically bonded to conductive layers 14 by any conventional technique such as soldering or through the use of a conductive adhesive. The final structure then may be encapsulated within insulating sheath 18.

The method of assembly of the structure of the present invention is as follows:

1. Prepare an elongated ceramic member of rectangular cross-section.

2. Form a capacitor ribbon by coating a pair of opposed side surfaces of the ceramic member with conductive material.

3. Electrically bond transversely extending bus bar distribution pins to the conductive coatings of the capacitor ribbon.

4. Encapsulating the assembly within an insulating sheath.

While a preferred embodiment of the present invention has been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of this invention. Accordingly, it will be understood that the present invention has been described by way of illustration and not limitation.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3310718 *7 Apr 196421 Mar 1967Nytronics IncImpedance element with alloy connector
US3778735 *4 May 197211 Dec 1973Co Europ Composants ElectroniqTransmission line of low characteristic impedance
GB1427524A * Title not available
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4584768 *3 Jul 198429 Apr 1986Mecondor S.P.A.Method of making high capacitive multilayer conductive bars
US4619752 *20 Feb 198528 Oct 1986Conradty Gmbh & Co. Metallelektroden KgElectrode for electrolytic extraction of metals or metal oxides
US4834673 *23 Aug 198830 May 1989Amp IncorporatedFlat cable power distribution system
US4867696 *15 Jul 198819 Sep 1989Amp IncorporatedLaminated bus bar with power tabs
US4869673 *3 Feb 198926 Sep 1989Amp IncorporatedCircuit panel assembly with elevated power buses
US4886468 *8 Dec 198812 Dec 1989General Electric CompanyInsulated electrical power distribution busway tabs
DE102012214159A1 *9 Aug 201213 Feb 2014Lisa Dräxlmaier GmbHMethod for contacting and connecting single-layer or multi-layer multi-rail with strand conductors in motor car, involves providing contact element with contact surface for contacting contact surfaces with conductive layers
EP0629108A1 *31 May 199414 Dec 1994Societe D'applications Generales D'electricite Et De Mecanique SagemSupply distribution bus bar for component support, the component support and distribution strips for joining the busbar with the support
U.S. Classification174/72.00B, 29/825, 29/860
International ClassificationH05K1/02, H05K1/16, H02G5/00
Cooperative ClassificationY10T29/49117, H05K1/0263, Y10T29/49179, H05K1/16, H02G5/005
European ClassificationH02G5/00C
Legal Events
3 Mar 1981ASAssignment
Effective date: 19810324
Effective date: 19810324
28 Feb 1987REMIMaintenance fee reminder mailed
19 Jul 1987LAPSLapse for failure to pay maintenance fees
6 Oct 1987FPExpired due to failure to pay maintenance fee
Effective date: 19870719